private final ImmutableBiMap<SeatId, PlayerId> seatMap;
public SitInState(GameState gameState, SitInEvent event) {
super(gameState);
this.event = event;
playerState = new SeatedPlayerState(event.getPlayer());
seatMap = (new ImmutableBiMap.Builder<SeatId, PlayerId>())
.putAll(super.getSeatMap())
.put(playerState.getSeatId(), playerState.getPlayerId())
.build();
}